Vascular device marker attachment

ABSTRACT

A medical device can include an elongate manipulation member, and a thrombectomy device connected to the elongate manipulation member. The thrombectomy device can have a first configuration and a second configuration, the thrombectomy device being expandable from the first configuration to the second configuration. The thrombectomy device can include an arcuate marker-mounting projection attached to a portion of the thrombectomy device configured to contact a thrombus. A marker can be coupled to, and extending around, the arcuate marker-mounting projection with the marker and the arcuate marker-mounting projection contacting each other at three discrete locations. A method for engaging a thrombus can include advancing a thrombectomy device to a location radially adjacent to a thrombus in a blood vessel. The thrombectomy device can be positioned such that a marker, disposed at a proximal end of a working length of thrombectomy device, is proximal to or longitudinally aligned with a proximal end of the thrombus, and can be expanded into the thrombus.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. patentapplication Ser. No. 15/043,463, filed Feb. 12, 2016, which isincorporated by reference herein in its entirety.

BACKGROUND OF THE DISCLOSURE

Blood vessels can become occluded by emboli, e.g., thrombi. For example,intracranial arteries can become occluded by thromboembolisms.Disruption of blood flow by the occlusion can prevent oxygen andnutrients from being delivered to tissues downstream of the occlusion.Deprivation of oxygen and nutrients to tissue distal to an occlusion canimpair proper function of the tissue, and may result in cellular death.Cellular death increases with duration of the occlusion.

SUMMARY OF THE DISCLOSURE

Markers can be used to assist an operator in determining the locationand/or orientation of a medical device within a blood vessel. Someaspects of the subject technology relate to attachment of a marker to athrombectomy or other medical device. Some aspects of the subjecttechnology relate to the positioning of one or more markers on athrombectomy device. Some aspects of the subject technology relate tothe use of markers in methods for removing thrombus from a blood vessel.

The subject technology is illustrated, for example, according to variousaspects described below. Various examples of aspects of the subjecttechnology are described as numbered clauses (1, 2, 3, etc.) forconvenience. These are provided as examples and do not limit the subjecttechnology. It is noted that any of the dependent clauses may becombined in any combination, and placed into a respective independentclause, e.g., clause 1, 12, 16, or 24. The other clauses can bepresented in a similar manner.

-   -   1. A medical device comprising:        -   an elongate manipulation member; and        -   a thrombectomy device connected to the elongate manipulation            member, the thrombectomy device having a first configuration            and a second configuration, the thrombectomy device being            expandable from the first configuration to the second            configuration; the thrombectomy device comprising a            plurality of arcuate marker-mounting projections each            attached to a portion of the thrombectomy device configured            to contact a thrombus and arranged such that any laterally            aligned arcuate marker-mounting projections are disposed            laterally farther from each other when the thrombectomy            device is in the second configuration than they are when the            thrombectomy device is in the first configuration    -   2. The medical device of clause 1, wherein each of the arcuate        marker-mounting projections comprises a concave surface.    -   3. The medical device of clause 2, wherein the concave surface        faces away from the portion of the thrombectomy device        configured to contact the thrombus to which the arcuate        marker-mounting projection is attached.    -   4. The medical device of clause 2, wherein each of the arcuate        marker-mounting projections comprises a convex surface opposite        the concave surface.    -   5. The medical device of clause 4, wherein the convex surface is        parallel to the concave surface.    -   6. The medical device of clause 1, wherein the thrombectomy        device comprises a plurality of struts forming a plurality of        cells, and each of the arcuate marker-mounting projections        extends from one of the struts.    -   7. The medical device of clause 6, wherein each of the arcuate        marker-mounting projections is separated from all of the other        arcuate marker-mounting projections by at least one strut        length.    -   8. The medical device of clause 1, further comprising a        plurality of markers, each marker being attached to only one of        the arcuate marker-mounting projections.    -   9. The medical device of clause 1, wherein at least one of the        marker-mounting projections is disposed at a proximal end of a        working length of the thrombectomy device.    -   10. The medical device of clause 9, wherein the least one of the        marker-mounting projection is within 5 millimeters of the        proximal end of the working length.    -   11. The medical device of clause 1, wherein a group of        marker-mounting projections is disposed at a proximal end of a        working length of the thrombectomy device.    -   12. A medical device comprising:        -   an elongate manipulation member;        -   a thrombectomy device connected to the elongate manipulation            member;        -   an arcuate marker-mounting projection extending from a            portion of the thrombectomy device configured to contact a            thrombus; and        -   a marker coupled to, and extending around, the arcuate            marker-mounting projection with the marker and the arcuate            marker-mounting projection contacting each other at three            discrete locations.    -   13. The medical device of clause 12, wherein the marker and the        marker-mounting projection contact each other at one location on        a convex side of the arcuate marker-mounting projection, and the        marker and the arcuate marker-mounting projection contact each        other at two locations on a concave side of the marker-mounting        projection.    -   14. The medical device of clause 13, wherein the one contact        location on the convex side is between the two contact locations        on the concave side.    -   15. The medical device of clause 13, wherein the convex side of        the arcuate marker-mounting projection and the concave side of        the marker-mounting projection are parallel.    -   16. A method for engaging a thrombus, the method comprising:        -   (a) advancing a thrombectomy device, using an elongate            manipulation member, to a location radially adjacent to a            thrombus in a blood vessel, the thrombectomy device            comprising a working length and a non-working length, the            non-working length disposed between and separating the            working length and a connection between the thrombectomy            device and the elongate manipulation member, the working            length having a proximal end and a distal end with a            proximal marker disposed at the proximal end, and a distal            marker, discrete from the proximal marker, disposed at the            distal end;        -   (b) positioning the thrombectomy device relative to the            thrombus such that the proximal marker is proximal to or            longitudinally aligned with a proximal end of the thrombus            and the distal marker is distal to or longitudinally aligned            with a distal end of the thrombus; and        -   (c), after (b), expanding the thrombectomy device into the            thrombus.    -   17. The method of clause 16, wherein a plurality of proximal        markers are disposed at the proximal end of the working length        and a plurality of distal markers are disposed at the distal end        of the working length, and wherein positioning the thrombectomy        device relative to the thrombus comprises positioning all of the        proximal markers proximal to or longitudinally aligned with a        proximal end of the thrombus and all of the distal markers        distal to or longitudinally aligned with a distal end of the        thrombus.    -   18. The method of clause 17, wherein a plurality of intermediate        markers is attached to the thrombectomy device between the        plurality of proximal markers and the plurality of distal        markers, the method further comprising determining whether a        maximum marker separation of the plurality of intermediate        markers is less than a maximum marker separation of either the        plurality of proximal markers or the plurality of distal        markers.    -   19. The method of clause 18 wherein, when the maximum marker        separation of the plurality of intermediate markers is not less        than the maximum marker separation of either the plurality of        proximal markers or the plurality of distal markers, the method        further comprises:        -   collapsing the thrombectomy device;        -   repositioning the thrombectomy device relative to the            thrombus such that the proximal marker is proximal to or            longitudinally aligned with a proximal end of the thrombus            and the distal marker is distal to or longitudinally aligned            with a distal end of the thrombus; and        -   re-expanding the thrombectomy device into the thrombus.    -   20. The method of clause 18 further comprising determining a        state of expansion of the working length by observing the        proximal, intermediate and distal pluralities of markers.    -   21. The method of clause 16, wherein the proximal marker is        located within 5 millimeters of the proximal end of the working        length.    -   22. The method of clause 21, wherein the thrombectomy device        includes a plurality of cells, and wherein the proximal marker        grouping is located within one cell-length of the proximal end        of the working length.    -   23. The method of clause 21, wherein the thrombectomy device        includes a generally cylindrical structure having a roll-up        configuration.    -   24. A method for engaging a thrombus, the method comprising:        -   (a) advancing a thrombectomy device, using an elongate            manipulation member, to a location radially adjacent to a            thrombus in a blood vessel, the thrombectomy device            comprising a working length having a proximal end and a            distal end with a proximal marker disposed at the proximal            end;        -   (b) positioning the thrombectomy device relative to the            thrombus such that the proximal marker is proximal to or            longitudinally aligned with a proximal end of the thrombus;            and        -   (c), after (b), expanding the thrombectomy device into the            thrombus.    -   25. The method of clause 24, wherein the thrombectomy device        further comprises a non-working length, the non-working length        disposed between and separating the working length and a        connection between the thrombectomy device and the elongate        manipulation member, the proximal marker being located distal of        the connection.    -   26. The method of clause 24, further comprising imaging the        proximal end of the working length distinctly from the        connection with the proximal marker.    -   27. The method of clause 24, wherein the thrombectomy device        further comprises a distal marker, discrete from the proximal        marker, disposed at the distal end of the working length.    -   28. The method of clause 27, further comprising positioning the        thrombectomy device such that the distal marker is distal to or        longitudinally aligned with a distal end of the thrombus.    -   29. The method of clause 27, wherein the thrombectomy device has        a body comprising a plurality of struts, and the distal and        proximal markers are more radiopaque than the body.    -   30. The method of clause 24, wherein a plurality of proximal        markers are disposed at the proximal end of the working length,        and wherein positioning the thrombectomy device relative to the        thrombus comprises positioning all of the proximal markers        proximal to or longitudinally aligned with a proximal end of the        thrombus.    -   31. The method of clause 30, wherein a plurality of intermediate        markers is attached to the thrombectomy device distal of the        plurality of proximal markers, the method further comprising        determining whether a maximum marker separation of the plurality        of intermediate markers is less than a maximum marker separation        of the plurality of proximal markers.    -   32. The method of clause 31, wherein, when the maximum marker        separation of the plurality of intermediate markers is not less        than the maximum marker separation of the plurality of proximal        markers, the method further comprises:        -   collapsing the thrombectomy device;        -   repositioning the thrombectomy device relative to the            thrombus such that the proximal marker is proximal to or            longitudinally aligned with a proximal end of the thrombus;            and        -   re-expanding the thrombectomy device into the thrombus.

Additional features and advantages of the subject technology will be setforth in the description below, and in part will be apparent from thedescription, or may be learned by practice of the subject technology.The advantages of the subject technology will be realized and attainedby the structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplifying and explanatory andare intended to provide further explanation of the subject technology asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding of the subject technology and are incorporated in andconstitute a part of this description, illustrate aspects of the subjecttechnology and, together with the specification, serve to explainprinciples of the subject technology.

FIG. 1 illustrates a medical device including a thrombectomy device,according to an embodiment.

FIG. 2 is a schematic illustration of overlap configurations of thethrombectomy device of FIG. 1.

FIG. 3 illustrates an exemplifying thrombectomy device in an unrolledstate.

FIG. 4 illustrates another exemplifying thrombectomy device in anunrolled state.

FIG. 5 is an enlarged view of a marker-mounting projection of thethrombectomy device shown in the area 5-5 of FIG. 4.

FIG. 6 illustrates the marker-mounting projection of FIG. 5 togetherwith a marker.

FIG. 7 is a schematic representation of a fluoroscopic image of anarrangement of markers when a thrombectomy device to which they areattached is in an unexpanded state.

FIG. 8 is a schematic representation of a fluoroscopic image of themarkers of FIG. 7 when the thrombectomy device to which they areattached is in a fully expanded state.

FIG. 9 is a schematic representation of a fluoroscopic image of themarkers of FIG. 7 when the thrombectomy device to which they areattached is partially expanded within a vessel and in contact with athrombus.

FIGS. 10-13 are cross-sectional views of a blood vessel and illustrate aprocesses of advancing and positioning a medical device, according tosome embodiments.

FIGS. 14-16 are cross-sectional views of the blood vessel shown in FIGS.10-13, and illustrate various clot positions and thrombectomy deviceconfigurations, according to some embodiments.

FIGS. 17-20 are cross-sectional views of a blood vessel and illustrateuses of a medical device according to some embodiments.

DETAILED DESCRIPTION OF THE SUBJECT TECHNOLOGY

The detailed description set forth below is intended as a description ofvarious configurations of the subject technology and is not intended torepresent the only configurations in which the subject technology may bepracticed. The appended drawings are incorporated herein and constitutea part of the detailed description. The detailed description includesspecific details for the purpose of providing a thorough understandingof the subject technology. However, the subject technology may bepracticed without these specific details. In some instances, well-knownstructures and components are shown schematically to avoid obscuring theconcepts of the subject technology.

FIG. 1 depicts an exemplifying medical device 100 according to someembodiments of the subject technology. As illustrated in FIG. 1, themedical device 100 can comprise a vascular device or thrombectomy device102 and a manipulation member 104. FIG. 1 also illustrates markers 150attached to the thrombectomy device 102. A proximal end portion of thethrombectomy device 102 and a distal end portion of the manipulationmember 104 can be joined at a connection 106. The manipulation member104 can extend through a catheter 107 such that an operator canmanipulate the thrombectomy device 102, positioned within and/or distalto a distal end of the catheter 107, using the manipulation member 104at a location proximal to a proximal end of the catheter 107.

The manipulation member 104 can be an elongate manipulation member. Themanipulation member 104 can have a length sufficient to extend from alocation outside the patient's body through the vasculature to atreatment site within the patient's body. For example, the manipulationmember can have a length of at least 100 cm, at least 130 cm, or atleast 150 cm. The manipulation member 104 can be monolithic or formed ofmultiple joined components. In some embodiments, the manipulation member104 can comprise a combination of wire(s), coil(s), and/or tube(s).

The thrombectomy device 102 and the manipulation member 104 can beattached together at the connection 106. In some embodiments, thethrombectomy device 102 and the manipulation member 104 can besubstantially permanently attached together at the connection 106. Thatis, the thrombectomy device 102 and the manipulation member 104 can beattached together in a manner such that, under the expected useconditions of the medical device 100, the endovascular device and themanipulation member would not become separated, whether deliberately orunintentionally, from one another without damage to or destruction of atleast a portion of the connection 106. In some embodiments, thethrombectomy device 102 and the manipulation member 104 can bepermanently or releasably attached together at the connection 106.

In some embodiments, the connection 106 can comprise a marker. Themarker of the connection can comprise a radiopaque material such asplatinum, iridium, tantalum, gold, alloys thereof or bismuth andtungsten-doped polymers, among other materials. The connection markercan be more radiopaque than a body of the vascular or thrombectomydevice 102. The connection marker can be visible under fluoroscopy, CATscans, X-Rays, Mill, ultrasound technology or other types of imaging.The connection marker can include an interior channel, an interiorrecess or another mounting feature. Further, the connection marker cancomprise a band or substantially cylindrical shape with an open orclosed circumference, a coil, or other form.

It optionally may be advantageous to have a connection mechanism thatpermits intentional release of the thrombectomy device 102. For example,during a blood flow restoration procedure, it may prove difficult and/ordangerous to fully retrieve a thrombus due to a complicated vasculatureor the risk of damaging a lumen wall. Leaving the thrombectomy device102 inside the patient may prove to be the only option available to asurgeon or other medical personnel, or it may be a goal of theprocedure, such as when the thrombectomy device 102 is deployed acrossan aneurysm (e.g., as an aneurysm bridge to retain coils or othermaterials in an aneurysm). In other circumstances the thrombectomydevice 102 may include drug-eluting capabilities, and/or may be coatedwith a particular type of drug that facilitates thrombus dissolution. Itmay be advantageous in such circumstances to release the thrombectomydevice 102 and allow the thrombectomy device 102 to anchor the thrombusagainst the lumen wall while the thrombus is dissolved by the drug. Insome embodiments, the medical device 100 can comprise a portion, locatedproximally or distally of the connection 106, that is configured forselective detachment of the thrombectomy device 102 from themanipulation member 104. For example, such a portion can comprise anelectrolytically severable or mechanically detachable segment of themanipulation member. In some embodiments, the medical device 100 can bedevoid of any feature that would permit selective detachment of thethrombectomy device 102 from the manipulation member 104.

As illustrated in FIGS. 1 and 2, the thrombectomy device 102 can have atubular or generally cylindrical shape in the absence of external forcesin some embodiments. However, in some embodiments, the thrombectomydevice can have a shape that is neither tubular nor cylindrical. In someembodiments, the thrombectomy device can have open proximal and distalends, for example as illustrated in FIGS. 1 and 2, while in otherembodiments, the thrombectomy device can have closed proximal and/ordistal ends. In some embodiments, the thrombectomy device can comprise aseries of structures (e.g., a longitudinal series of structures) eachhaving proximal and distal ends that are open or closed. In someembodiments, the thrombectomy device can comprise a tubular orcylindrical structure disposed within, around, or radially overlappingsuch a series of structures or one or more other tubular or cylindricalstructure(s). The thrombectomy device 102 can be self-expanding, e.g. bysuper-elasticity or shape memory, or expandable in response to forcesapplied on the expandable member, e.g. by a balloon.

As shown in FIGS. 1 and 2, the thrombectomy device 102 in someembodiments can be curled, rolled, or otherwise formed such that a firstedge 124 and a second edge 126 overlap one another, or form a gapbetween each other, when the thrombectomy device 102 is in avolume-reduced form. In a volume-reduced form, or an unexpanded form,the thrombectomy device 102 illustrated in FIGS. 1 and 2 can overlapitself to facilitate introduction of the thrombectomy device 102 intoand through the catheter 107. FIG. 2 is a schematic illustration ofoverlap configurations (e.g., various amounts of overlap) of thethrombectomy device of FIG. 1. FIG. 2 illustrates various amounts ofoverlap of the thrombectomy device 102, forming zones of overlap 128.The thrombectomy device 102 can assume various diameters Δ₁, Δ₂, etc.,depending on the degree of the overlap (e.g. represented by angle α₁,α₂, etc.). The extent of any overlap of a frame 108 of the vascular orthrombectomy device can depend upon a degree of the frame's expansion.Expansion within a vessel can be limited, at least in part, by thevessel's size, and the amount and the properties of any thrombuspresent. For example, a greater overlap of the edges 124, 126 can occurin narrower vessels, whereas in wider vessels the overlap can besmaller, or even an “underlap” may occur, in which case the edges 124and 126 are separated by an open gap or space within the vessel.Advantageously, the presence of an overlap or “roll-up” configurationallows the thrombectomy device to be expanded or compressed in diameterwith little or no change in length (e.g. foreshortening duringexpansion), in comparison to a similar device that lacks the overlap orroll-up configuration. This is because the expansion or compression canresult from a decrease or increase in degree of overlap (see FIG. 2)rather than wholly from deformation of the struts 114 and cells 116(FIG. 3), which deformation can decrease or increase the length of thedevice when transitioning to the expanded or compressed state.

In some embodiments, the thrombectomy device 102 is circumferentiallycontinuous (e.g., forming a circumferentially continuous tubular orcylindrical shape), lacking first and second edges 124, 126 and havingno overlap or gap in a volume-reduced form and expanded form. Regardlessof whether the thrombectomy device is circumferentially continuous, thethrombectomy device 102 can have a central longitudinal axis both whilein a volume-reduced form and when fully or partially expanded. In someembodiments, the thrombectomy device 102 can be self-expandable, and canexpand toward a fully expanded configuration upon release from thecatheter 107. Upon expansion, the thrombectomy device 102 can expandtowards an inner wall of a vessel, towards an occlusive orpartially-occlusive thrombus, clot or embolus within a vessel, or both.

The thrombectomy device 102 can be oversized relative to the interior ofa vessel in which it is to be used, or the thrombectomy device 102 canoccupy a larger volume when allowed to expand outside a vessel than whenallowed to expand inside a vessel. In other words, the vessel mayprevent a complete expansion of some or all of the thrombectomy device102.

Upon thrombectomy device 102 expansion into an expanded configuration,portions of the thrombectomy device can to penetrate into a thrombus,capture a thrombus, or both. In some embodiments, the thrombectomydevice 102 can capture the thrombus with an exterior, or radialexterior, of the expanded thrombectomy device 102. Additionally oralternatively, in some embodiments, the thrombectomy device 102 maycontact, interlock, capture or engage with a portion of the thrombuswith an interior, or radial interior, of the expanded thrombectomydevice 102.

The thrombectomy device can comprise a working length and a non-workinglength. The portion of the thrombectomy device 102 in the working lengthis configured to interlock, capture or engage a thrombus. The portion ofthe thrombectomy device in the non-working length may contact thromboticmaterial in use, but is configured to perform a function that renders itineffective or less effective other than the working length forinterlocking, capturing or engaging with a thrombus. In someembodiments, the non-working length is disposed between the workinglength and the connection 106 to the manipulation member 104.

In some embodiments, the working length of the thrombectomy device 102can comprise a repeating pattern of structural features. For example, aworking portion of the thrombectomy device 102 illustrated in FIGS. 1and 2 comprises a matrix of cells. Nonetheless, in some embodiments therepeating pattern of structural features can have other forms.

FIG. 3 illustrates an exemplifying the vascular device or thrombectomydevice 102 in a flat configuration to facilitate understanding ofvarious features present in some thrombectomy devices according tovarious embodiments. The thrombectomy device 102 illustrated in FIG. 3includes a working length 144 and a non-working length 145. Asillustrated in FIG. 3, for example, the non-working length 145 isdisposed between the working length 144 and the connection 106 to themanipulation member 104.

As illustrated in FIG. 3, in some embodiments, the thrombectomy devicecan comprise a frame or body 108 having a plurality of struts 114 and aplurality of cells 116, forming a mesh. Groups of longitudinally andserially interconnected struts 114 can form undulating members 118 thatextend in a generally longitudinal direction. The struts 114 can beconnected to each other by joints 120. While the struts are shown havinga particular undulating or sinuous configurations, in some embodimentsthe struts can have other configurations. The frame of the thrombectomydevice can have a generally tubular or generally cylindrical shape insome embodiments, while in others the frame can have a shape that isneither tubular nor cylindrical.

The working length 144 of the thrombectomy device illustrated in FIG. 3comprises some of the cells 116. In embodiments wherein the thrombectomydevice 102 comprises cells, the cells 116 in the working length and theportion of the thrombectomy device that form them can be sized andshaped such that they penetrate into a thrombus, capture a thrombus, orboth upon expansion of the working length into a thrombus. In someembodiments, the portion of the thrombectomy device 102 in the workinglength can capture the thrombus with the individual cells 116 and/orwith an exterior, or radial exterior, of the expanded thrombectomydevice 102. Additionally or alternatively, in some embodiments, theportion of the thrombectomy device 102 in the working length maycontact, interlock, capture or engage with a portion of the thrombuswith individual cells 116 and/or an interior, or radial interior, of theexpanded thrombectomy device 102.

As illustrated in FIG. 3, for example, the non-working length cancomprise a tapered proximal portion 122 of the thrombectomy device 102.The proximal portion 122 of the thrombectomy device 102 can be taperedtoward a proximal end 110 of the thrombectomy device 102. In someembodiments, the taper of the proximal, non-working portion 122 canadvantageously facilitate retraction and repositioning of the medicaldevice 100 and thrombectomy device 102. For example, in someembodiments, the non-working length 145 facilitates a retraction of thethrombectomy device 102 into the catheter 107.

In some embodiments, the tapered proximal, non-working portion 122 canbe additionally or alternatively designed to generally not contact thevessel wall during a blood flow restoration procedure, and to generallynot interfere with the flow of blood within a vessel.

The taper of proximal portion 122 can be at various angles relative tothe manipulation member 104 or the longitudinal axis of the thrombectomydevice 102. For example, in some embodiments, the taper can have anangle of approximately 45 degrees relative to the manipulation member,though other angles are also possible, and within the scope of thepresent disclosure.

The thrombectomy device 102 can comprise a first edge 124 and a secondedge 126. The first edge 124 and second edge 126 can be formed, forexample, from cutting a sheet or a tube. While the first and secondedges are shown as having an undulating, or sinuous configuration, insome embodiments the first and second edges can have a straight, orlinear configuration, or other configuration. In some embodiments, theedges 124, 126 can be curved, straight, or a combination thereof alongthe tapered proximal portion 122.

Each cell 116 of the thrombectomy device 102 can have a maximum length(labeled “L” in FIG. 3), as measured along a longitudinal axis of thethrombectomy device 102, and a maximum width W, as measured along adirection generally perpendicular to the length (labeled “W” in FIG. 3).FIG. 3 illustrates an embodiment of the thrombectomy device 102 having apattern 130 of cells 116 of substantially uniform dimensions and struts114 of substantially uniform dimensions. Nonetheless, in someembodiments, cell size and dimensions can vary along the length and wideof the frame 108, as can the individual filament thicknesses and widths.

FIG. 3 also illustrates a plurality of marker-mounting projections 148.Each marker-mounting projection 148 can be attached to a portion of thethrombectomy device 102 that may contact thrombus during use of thethrombectomy device. In some embodiments, the marker-mountingprojections 148 can be attached to portions of the thrombectomy device102 in the working length 144, for example as illustrated in FIG. 3. Inembodiments wherein the thrombectomy device comprises struts 114, themarker-mounting projection(s) 148 can be attached to a strut 114. Themarker-mounting projection 148 can be disposed within a cell 116, ifpresent, or on another surface of the thrombectomy device 102. In someembodiments, a plurality of marker-mounting projections 148 can beattached respectively to a plurality of struts 114. In some embodiments,some or all of the marker-mounting projections 148 can each be attachedto and/or at only a single strut 114. In some embodiments, themarker-mounting projection 148 can be attached to and/or at a joint 120.In some embodiments, the marker-mounting projections 148 can beseparated from all other marker-mounting projections 148 by a distance,for example at least 2 mm or at least 3 mm, in a fully expandedconfiguration of the thrombectomy device 102. In some embodiments, themarker-mounting projections 148 can be separated from all othermarker-mounting projections 148 by one cell width or one strut length(e.g, an entire length of a strut separates the adjacent marker-mountingprojections).

One or more marker-mounting projections 148 can be located at some orall of a proximal end 146 of the working length 144, a distal end 147 ofthe working length 144, or an intermediate area 149 of the workinglength 144 between the proximal end 146 and the distal end 147. Theworking length 144 can extend continuously or intermittently between theproximal end 146 and the distal end 147.

In some embodiments, the proximal end of the working length can be at aproximalmost location where the thrombectomy device forms a completecircumference. In some embodiments, the proximal end of the workinglength can be at a proximalmost location where the thrombectomy devicehas its greatest transverse dimension in a fully expanded state. In someembodiments, the proximal end of the working length can be at aproximalmost location where the thrombectomy device has a peak, crown,or crest in transverse dimension in a fully expanded state.

In some embodiments, the distal end of the working length can be at adistalmost location where the thrombectomy device forms a completecircumference. In some embodiments, the distal end of the working lengthcan be at a distalmost location where the thrombectomy device has itsgreatest transverse dimension in a fully expanded state. In someembodiments, the distal end of the working length can be at a distalmostlocation where the thrombectomy device has a peak, crown, or crest intransverse dimension in a fully expanded state.

In some embodiments, a marker-mounting projection 148 located at theproximal end 146 can be disposed within 5 mm, within 4 mm, within 3 mm,within 2 mm, or within 1 mm, proximally or distally, of the proximal end146. In some embodiments, a marker-mounting projection 148 located atthe proximal end 146 can be disposed within the length of one cell orone strut, proximally or distally, of the proximal end 146.

In some embodiments, a marker-mounting projection 148 located at thedistal end 147 can be disposed within 5 mm, within 4 mm, within 3 mm,within 2 mm, or within 1 mm, proximally or distally, of the distal end147. In some embodiments, a marker-mounting projection 148 located atthe distal end 147 can be disposed within the length of one cell or onestrut, proximally or distally, of the distal end 147.

A plurality or group of marker-mounting projections 148 can be locatedat some or all of the proximal end 146, the distal end 147, or theintermediate area 149. In some embodiments, the plurality or group ofmarker-mounting projections 148 at each of these locations (if present)have a common pattern. For example, the projections 148 in the pluralityor group at the proximal end 146 can have the same arrangement relativeto each other as do the projections 148 in the plurality or group at thedistal end 147. The projections 148 in the plurality or group atintermediate area 149 (if present) can have the same arrangementrelative to each other as do the projections 148 in the plurality orgroup at each of the proximal end 146 and the distal end 147, forexample as illustrated in FIG. 3. In some embodiments, themarker-mounting projections 148 of such a plurality or group ofmarker-mounting projections 148 can be disposed farther from each otherwhen the thrombectomy device 102 is in an expanded configuration thatthey are when the thrombectomy device 102 is in an unexpanded or lessexpanded configuration.

In some embodiments, the vascular or thrombectomy device 102 cancomprise one or more distally extending tips extending from a distal endof the thrombectomy device. For example, the device illustrated in FIG.3 is shown comprising four elongate, distally extending tips 154extending from a distal end of the thrombectomy device 102. In someembodiments wherein the thrombectomy device comprises struts, thesedistal tips 154 can extend from a distalmost row of struts, for exampleas illustrated in FIG. 3. In some embodiments, one or more markers 150can be attached to the distal tips 154, if present. In some embodimentswherein one or more markers 150 are attached to the distal tips, themarker(s) 150 on the distal tips 154 can be positioned at the distal end147 of the working length 144, for example as illustrated in FIG. 3.FIG. 4 illustrates another exemplifying the thrombectomy device 102 in aflat configuration to facilitate understanding of various featurespresent in some thrombectomy devices according to various embodiments.FIG. 4 shows sets of marker-mounting projections 148 arranged orlaterally aligned such that they lie along straight lines R1, R2, R3that are parallel to a longitudinal axis of the thrombectomy device 102in the absence of external forces on the thrombectomy device. However,when external forces are applied, the lines R1, R2, R3 through one ormore of the sets of marker-mounting projections may not be straightand/or may not be parallel to the longitudinal axis of the thrombectomydevice.

In some embodiments, the markers in a laterally aligned set orlongitudinally grouped set can be separate and/or spaced from each otherand from the markers in other sets and/or groups.

FIGS. 5 and 6 are enlarged views of a marker-mounting projection 148shown in the area 5-5 of FIG. 4. In some embodiments, themarker-mounting projection 148 has an arcuate, bowed or curved shape,and such a shape can span an entirety of the length of themarker-mounting projection 148 that receives a marker 150. In someembodiments, the marker-mounting projection 148 can be cantilevered fromthe portion of the thrombectomy device to which it is attached (e.g.,from a strut 114, if present).

As illustrated in FIGS. 5 and 6, the marker-mounting projection 148 caninclude a concave surface 160 and a convex surface 162. However, somemarker-mounting projections can have a concave surface 160 or a convexsurface 162 (either without the other), or neither. In some embodiments,the concave surface 160 faces away from a portion of the thrombectomydevice 102 to which to is attached (e.g., from a strut 114, if present).In some embodiments, the convex surface 162 is arranged opposite fromthe concave surface 160, facing toward a portion of the thrombectomydevice 102 to which to is attached (e.g., toward a strut 114, ifpresent), or both.

In some embodiments, the concave surface 160 and the convex surface 162are parallel to each other over some or all of the length of themarker-mounting projection 148 that receives a marker 150. Themarker-mounting projection 148 can comprise a constant cross-sectionalarea along its length and/or a constant width along the length of themarker-mounting projection 148 that receives a marker 150. In someembodiments, the concave surface 160, the convex surface 162, or bothincludes a constant curvature or radius along the length of themarker-mounting projection 148 that receives a marker 150. In someembodiments, the marker-mounting projection 148 includes a roundeddistal end 163.

FIG. 6 illustrates a marker 150 on the marker-mounting projection 148.The marker 150 can comprise a radiopaque material such as platinum,iridium, tantalum, gold, alloys thereof or bismuth and tungsten-dopedpolymers, among other materials. The marker 150 can be more radiopaquethan a body of the vascular or thrombectomy device 102. The marker 150can be visible under fluoroscopy, CAT scans, X-Rays, Mill, ultrasoundtechnology or other types of imaging. The marker 150 can include aninterior channel, an interior recess or another mounting feature.Further, the marker 150 can comprise a band or substantially cylindricalshape with an open or closed circumference, a coil, or another form thatmounts around a marker-mounting projection 148.

The marker 150 can directly attach to the marker-mounting projection 148through direct contact between the marker 150 and the marker-mountingprojection 148. In some embodiments, adhesives, welding, soldering,friction or mechanical fastening (e.g., crimping) directly attach themarker 150 to marker-mounting projection 148. In some embodiments, themarker 150 extends completely around the marker-mounting projection 148when the marker 150 is mounted, or directly attached, to themarker-mounting projection 148. In another embodiment, the marker 150extends partially (e.g., at least three quarters of the perimeter)around the marker-mounting projection 148 when the marker 150 ismounted, or directly attached, to the marker-mounting projection.

The marker-mounting projection 148 can extend generally parallel to asegment of the thrombectomy device (e.g., a strut) adjacent to themarker 150, for example as illustrated in FIG. 5, or such that a markerwhen mounted to the marker-mounting projection 148 is parallel to asegment of the thrombectomy device (e.g., a strut) adjacent to themarker 150, for example as illustrated in FIG. 6.

The marker 150 and the marker-mounting projection 148 can contact eachother at three discrete locations when the marker 150 is directlyattached to the marker mounting projection 148. In some embodiments, themarker 150 and the marker-mounting projection 148 contact each other atmore or fewer than three locations when the marker 150 is directlyattached to the marker mounting projection 148. In other embodiments,the marker 150 and the marker-mounting projection 148 contact each otherat two locations on the concave surface 160 and at one location on theconvex surface 162 when the marker 150 is directly attached to themarker-mounting projection 148. In one embodiment, the contact locationof the marker 150 and the convex surface 162 is located between thecontact locations of the marker 150 and the concave surface 160.

In some embodiments, an arcuate marker-mounting projection can havegreater marker retention strength, better withstand electropolishing, orboth compared to marker-mounting projection having a straightconfiguration.

FIGS. 7-9 are schematic representations of fluoroscopic images of anarrangement of markers when a thrombectomy device to which they areattached is in various states. FIG. 7 illustrates an arrangement ofmarkers 150 when the thrombectomy device 102 is in an unexpanded statewithin a catheter 107 (see FIG. 1). As shown in FIG. 7, the markers 150in a proximal marker group 151, which can be located at the workinglength proximal end 146 and mounted on marker-mounting projections 148,markers 150 in a distal marker group 152, which can be located at theworking length distal end 147 and mounted on marker-mounting projections148, and markers 150 in an intermediate marker group 153, which can belocated at the working length intermediate area 149 and mounted onmarker-mounting projections 148, can be in close lateral proximity tothe other markers 150 in the respective marker group. In someembodiments, a portion of a length of the thrombectomy device 102between the proximal marker group 151 and the distal marker group 152,or between the working length proximal 146 and distal 147 ends, has nomarker 150.

FIG. 8 illustrates the markers of FIG. 7 when the thrombectomy device102 is in a fully expanded state. As shown in FIG. 8, the markers 150 inthe proximal marker group 151, the markers 150 in the distal markergroup 152, and the markers 150 in the intermediate marker group 153 canbe located farther laterally from the other markers 150 in a respectivemarker group in this state than they are when the thrombectomy device102 is in an unexpanded state. FIG. 8 also shows the markers havingsubstantially the same pattern and/or spacing relative to each other ineach of the proximal marker group 151, the distal marker group 152, andthe intermediate marker group 153.

FIG. 9 illustrates the markers of FIG. 7 when the thrombectomy device102 is in a partially expanded state within a vessel and in contact witha thrombus. As shown in FIG. 9, markers 150 in the intermediate markergroup 153 are not spaced as far from each other laterally as are themarkers 150 in the proximal marker group 151 from each other or themarkers 150 in the distal marker group 152 are from each other. Such anarrangement can occur when the thrombectomy device 102 is in an expandedstate in the presence of a thrombus 165 that inhibits or preventsexpansion of a region of the thrombectomy device.

Methods for engaging and removing a thrombus 165 will now be discussedwith reference to FIGS. 10-20. Referring to FIG. 10, the medical device100 may be inserted into an anatomical vessel 172 by first inserting aguide wire 174 into the anatomical vessel 172. The illustratedanatomical vessel is an intracranial blood vessel. In some embodiments,the medical device is introduced into a segment of cerebral blood vesseldistal to the carotid siphon. The inserted medical device 100 can be anyembodiment of the medical device 100 disclosed herein, including any ofthe thrombectomy devices 102, elongate members 104, or connections 106.The guide wire 174 can be advanced through a guide catheter 164 (seeFIG. 18), which optionally includes a balloon near the guide catheter'sdistal end, and/or a catheter 107 to the treatment site, adjacent thethrombus 165. Referring to FIG. 11, the guide wire 174 is advanceddistally through the thrombus 165. Once the guide wire 174 is inposition, the catheter 107 is advanced over the guide wire 174, througha distal end of the guide catheter, toward the thrombus 165 in theanatomical vessel 172. Referring to FIG. 12, the catheter 107 isadvanced distally through the thrombus 165. The guide wire 174 is thenwithdrawn proximally.

Referring to FIG. 13, the medical device 100 is advanced through thecatheter 107. The medical device 100 is advanced through the catheter107 by the manipulation member 104 coupled to the thrombectomy device102 (e.g., at the proximal end of the thrombectomy device). The catheter107 prevents expansion of the thrombectomy device 102 and thus maintainsthe thrombectomy device 102 in a compressed, volume-reducedconfiguration as the thrombectomy device 102 is advanced to thetreatment site. The thrombectomy device 102 is advanced or otherwisemoved to position (i) the proximal marker or marker group 151 proximalto a proximal end 170 of the thrombus 165, and (ii) the distal marker ormarker group 152 distal to a distal end 171 of the thrombus 165. If anintermediate marker or marker group 153 is present, the thrombectomydevice 102 is advanced or otherwise moved to position the intermediatemarker or marker group 153 between the proximal and distal ends of(e.g., within) the thrombus.

Turning to FIG. 14, the catheter 107 is then withdrawn proximallyrelative to the thrombectomy device 102 to expose the thrombectomydevice 102. If the thrombectomy device 102 is self-expanding, retractionof the catheter 107 can permit the thrombectomy device 102 to expand toan expanded state. FIG. 14 illustrates the markers 150 of the proximalmarker group 151 and the distal marker group 152 as more expanded thanare the markers 150 of the intermediate 153 marker group, which appearin a less expanded distribution. Such an arrangement can result when thethrombectomy device 102 is expanded while all markers 150 of theproximal marker group 151 are located proximal to the thrombus 165, orto a proximal end of the thrombus 170, and all markers 150 of the distalmarker group 152 are located distal to the thrombus 165, or to a distalend of the thrombus 171. When such a marker 150 arrangement is observed,an operator may check, by injecting contrast solution through thecatheter 107 or guide catheter 164, for perfusion of the distalvasculature through the thrombus 165 via a flow channel (if any) openedin the thrombus 165 by the expansion of the thrombectomy device 102,allow the thrombectomy device 102 to continue expanding into thethrombus 165 and/or proceed to withdraw the thrombectomy device 102, asillustrated in FIG. 17.

FIG. 15 illustrates another configuration of the thrombectomy device102, wherein the markers 150 of the distal marker group 152 are moreexpanded than are the markers 150 of the proximal marker group 151 orthe marker group intermediate 153, which each appear in a less expandedstate. Such an arrangement can result when the thrombectomy device 102is expanded while all markers in the proximal marker group 151 and theintermediate marker group 153 are located radially adjacent to thethrombus 165 within the blood vessel and all markers in the distalmarker group 152 are located distal to the thrombus 165 or a distal end171 of the thrombus. When such a marker 150 arrangement is observed, anoperator may check for perfusion of the distal vasculature through thethrombus 165, allow the thrombectomy device 102 to continue expandinginto the thrombus 165 and/or proceed to withdraw the thrombectomy device102, as illustrated in FIG. 17.

FIG. 16 illustrates another configuration of the thrombectomy device102, wherein the markers 150 of the proximal marker group 151 are moreexpanded than are the markers 150 of the distal marker group 152 orintermediate marker group 153, which appear in less expanded state. Suchan arrangement can result when the thrombectomy device 102 is expandedwhile the markers in the distal marker group 152 are not located distalto the thrombus 165 or a distal end 171 of the thrombus or when thethrombus migrates distally during or after expansion of the thrombectomydevice 102.

When a marker 150 arrangement as illustrated in FIG. 16 is observed ordetermined, or when a maximum marker 150 separation of the intermediatemarker group 153 is observed as greater than a maximum marker 150separation of either the proximal marker group 151 or distal markergroup 152, an operator may elect to collapse the thrombectomy device 102into less unexpanded state, for example by advancing the catheter 107over the thrombectomy device 102. The operator can then again positionthe thrombectomy device 102 relative to the thrombus and expand thethrombectomy device as described above.

With the proximal marker or marker group 151 located at the workinglength proximal end 146, the operator can more accurately and/orconfidently position the thrombectomy device relative to a thrombusprior to expansion, thereby facilitating utilization of the workinglength of the thrombectomy device. In some embodiments, positioning thethrombectomy device 102 with reference to the proximal marker or markergroup 151 located at the working length proximal end 146 can facilitateor promote a successful removal of the thrombus or clot 165, byachieving a more secure contact, interlock or engagement between thethrombectomy device 102 and the thrombus or clot 165. Further, acomparison of the relative extent of marker group expansion can provideinformation to an operator that assists in determining whether and how(e.g., which direction) to reposition the thrombectomy device 102.

Accordingly, during a revascularization procedure, the user can use theproximal marker group 151 and/or the distal marker group 152 to properlylocate the thrombectomy device 102 longitudinally relative to thethrombus 165 before expanding the device 102 into the thrombus. Atappropriate time(s) in the procedure, the user can establish thelocation of the thrombus on an image of the treatment location (such asa fluoroscopic image or other suitable image as disclosed herein) byinjecting contrast media into the target vessel 172 and observing theeffect of the thrombus on the flow of the contrast media in the vessel.Once the catheter 107 is positioned in the thrombus 165 as shown in FIG.12, the user can advance the thrombectomy device 102 toward the distalend of the catheter and observe in the image of the treatment locationthe position of the proximal marker group 151 and/or the distal markergroup 152 relative to the thrombus 165 (e.g. relative to the proximalend 170 and/or the distal end 171 thereof). This can be done while thethrombectomy device 102 is still in the catheter to enable adjustment ofthe position of the thrombectomy device 102 prior to expansion; FIG. 7depicts an example of a fluoroscopic image that the user might observewith the proximal marker group 151 and the distal marker group 152clearly visible due to their radiopacity. The user can also observe fromsuch an image that the entire device 102 is still in the catheter 107due to the closely “packed” state of the marker groups 151, 152, 153(and as well that the distal end of device 102 is near the distal tip ofthe catheter 107 as may be facilitated by a catheter tip marker 173 (seeFIGS. 7-9). With the location of the proximal end of the working length144 indicated in the image by the proximal marker group 151 (and,optionally, the distal end of the working length 144 indicated in theimage by the distal marker group 152), the user can determine whetherthe proximal end of the working length 144 is positioned proximal of orlongitudinally aligned with the proximal end 170 of the thrombus (and,optionally, whether the distal end of the working length 144 ispositioned distal of or longitudinally aligned with the distal end 171of the thrombus). Based on this observation, the user can either confirmthat the working length 144 of the device 102 is aligned with (or spansthe entirety of) the length of the thrombus 165; if either or both isthe case the user can leave the device in its current longitudinalposition relative to the thrombus; if not, the user can adjust thelongitudinal position of the device 102 until it is correctly positionedrelative to the thrombus 165 as described above. Once the user hasconfirmed the correct positioning of the device 102 in this manner, theuser can proceed to expand the device 102 into the thrombus 165, e.g. asdescribed elsewhere herein, and remove some or all of the thrombus fromthe vessel 172. Advantageously, as mentioned above, when thethrombectomy device 102 is of an overlap or roll-up configuration,relatively little or no change in the length of the device 102 willoccur during expansion, and accordingly the positions of the markersrelative to the thrombus (and to each other) will not changesignificantly or at all as the device expands. This in turn facilitatesaccurate placement of the expanded device 102 in and relative to thethrombus 165.

Referring to FIGS. 17 and 18, once the user is satisfied that the device102 has been properly located longitudinally relative to the thrombus165 and expanded into it, the thrombectomy device 102 can be withdrawnproximally, along with the thrombus 165. As illustrated in FIG. 18, thethrombectomy device 102 can be withdrawn proximally, along with thethrombus 165, into the guide catheter 164.

Referring to FIGS. 18 and 19, in embodiments wherein the guide catheter164 comprises a balloon 168, the balloon optionally can be inflated toocclude flow during retraction of the thrombus 165 toward the guidecatheter. Referring to FIG. 18, the thrombectomy device 102 is withdrawnproximally to the guide catheter 164. The guide catheter 164 causes theframe 108 to collapse, with the thrombus 165 engaged therein. Thethrombus 165 is thus retrieved and removed from the anatomical vessel172. Referring to FIG. 20, if retrieval of the thrombectomy device 102is determined to be undesirable, e.g., to avoid damaging the vessel 172,and the thrombectomy device 102 is detachably or releasably connected tothe manipulation member 104, the thrombectomy device 102 can be detachedfrom the manipulation member 104 and can remain in the vessel 172.

Additionally, while the thrombectomy device 102 described above has beendescribed in the context of use during a thrombectomy or blood flowrestoration procedure, the thrombectomy device 102 can also, oralternatively, be used as an implantable member (e.g. stent). Forexample, the thrombectomy device 102 can be released through theconnection 106 at a stenosis, aneurysm, or other appropriate location ina vessel. The thrombectomy device 102 can expand and engage a vesselwall so as to hold the vessel wall open and/or act as an occludingmember. While the filament thicknesses, widths, cell sizes, and forcesdescribed above can be optimized for an thrombectomy device 102 for flowrestoration, these values can also be optimized for an thrombectomydevice 102 for use as an implantable member. In some embodiments thesame values can be used for both flow restoration and use as animplantable member.

Also, while use of the thrombectomy device 102 described above with useof a catheter 107, the catheter 107 can be omitted in some embodiments.

The foregoing description is provided to enable a person skilled in theart to practice the various configurations described herein. While thesubject technology has been particularly described with reference to thevarious figures and configurations, it should be understood that theseare for illustration purposes only and should not be taken as limitingthe scope of the subject technology.

There may be many other ways to implement the subject technology.Various functions and elements described herein may be partitioneddifferently from those shown without departing from the scope of thesubject technology. Various modifications to these configurations willbe readily apparent to those skilled in the art, and generic principlesdefined herein may be applied to other configurations. Thus, manychanges and modifications may be made to the subject technology, by onehaving ordinary skill in the art, without departing from the scope ofthe subject technology.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplifying approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Some of the stepsmay be performed simultaneously. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

A phrase such as “an aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples of the disclosure. A phrasesuch as “an aspect” may refer to one or more aspects and vice versa. Aphrase such as “an embodiment” does not imply that such embodiment isessential to the subject technology or that such embodiment applies toall configurations of the subject technology. A disclosure relating toan embodiment may apply to all embodiments, or one or more embodiments.An embodiment may provide one or more examples of the disclosure. Aphrase such “an embodiment” may refer to one or more embodiments andvice versa. A phrase such as “a configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A configuration may provide one or moreexamples of the disclosure. A phrase such as “a configuration” may referto one or more configurations and vice versa.

Furthermore, to the extent that the term “include,” “have,” or the likeis used in the description or the claims, such term is intended to beinclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically stated, but rather “one or more.” Theterm “some” refers to one or more.

All structural and functional equivalents to the elements of the variousconfigurations described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and intended to beencompassed by the subject technology. Moreover, nothing disclosedherein is intended to be dedicated to the public regardless of whethersuch disclosure is explicitly recited in the above description.

While certain aspects and embodiments of the subject technology havebeen described, these have been presented by way of example only, andare not intended to limit the scope of the subject technology. Indeed,the novel methods and systems described herein may be embodied in avariety of other forms without departing from the spirit thereof. Theaccompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thesubject technology.

1-15. (canceled)
 16. A medical device comprising: an elongatemanipulation member; and a thrombectomy device coupled to the elongatemanipulation member, the thrombectomy device extending between a firstend and a second end and expandable from a first configuration to asecond configuration, the thrombectomy device comprising (i) a pluralityof arcuate marker-mounting projections, each attached to a portion ofthe thrombectomy device configured to contact a thrombus, (ii) aplurality of struts forming a plurality of cells, each of theprojections extending from one of the struts disposed between the firstand second ends of the thrombectomy device, and (iii) a plurality ofmarkers, each marker being attached to one of the arcuatemarker-mounting projections, wherein at least some of themarker-mounting projections are laterally aligned in the absence ofexternal forces on the thrombectomy device, and wherein at least some ofthe laterally aligned marker-mounting projections are arranged such thatthey are disposed laterally farther from each other when thethrombectomy device is in the second configuration than they are whenthe thrombectomy device is in the first configuration.
 17. The medicaldevice of claim 16, wherein each of the projections comprises a concavesurface.
 18. The medical device of claim 17, wherein each of the concavesurfaces faces away from the strut to which it is attached such thateach of the concave surfaces faces towards an interior of thecorresponding cell.
 19. The medical device of claim 17, wherein each ofthe projections comprises a convex surface opposite the concave surface.20. The medical device of claim 19, wherein the convex surface isparallel to the concave surface.
 21. The medical device of claim 16,wherein each of the projections is separated from all of the otherprojections by at least one strut length.
 22. The medical device ofclaim 16, wherein at least one of the projections is disposed at aproximal end of a working length of the thrombectomy device, and whereinthe proximal end of the working length is distal to and spaced apartfrom the proximal end of the thrombectomy device.
 23. The medical deviceof claim 22, wherein the least one of the projections is within 5millimeters of the proximal end of the working length.
 24. The medicaldevice of claim 16, wherein a plurality of the projections are disposedat a proximal end of a working length of the thrombectomy device, andwherein the proximal end of the working length is distal to and spacedapart from the proximal end of the thrombectomy device.
 25. The medicaldevice of claim 16, wherein each of the markers is generallycylindrical.
 26. The medical device of claim 16, wherein each of theprojections is cantilevered from the strut of the thrombectomy device towhich it is attached.
 27. A medical device comprising: an elongatemanipulation member; a thrombectomy device connected to the elongatemanipulation member, the thrombectomy device having a plurality ofstruts forming a plurality of cells; an arcuate marker-mountingprojection extending from one of the struts disposed along a portion ofthe thrombectomy device configured to contact a thrombus; and a markercoupled to and extending around the projection, and wherein the markerand the projection contact each other at three discrete locations. 28.The medical device of claim 27, wherein the marker and the projectioncontact each other at one location on a convex side of the projection,and the marker and the projection contact each other at two locations ona concave side of the projection.
 29. The medical device of claim 28,wherein the one contact location on the convex side is between the twocontact locations on the concave side.
 30. The medical device of claim28, wherein the convex side of the projection and the concave side ofthe projection are parallel.
 31. The medical device of claim 27, whereinthe marker is generally cylindrical.
 32. The medical device of claim 27,wherein the projection is cantilevered from the strut of thethrombectomy device to which it is attached.
 33. The medical device ofclaim 27, wherein the projection is disposed at a proximal end of aworking length of the thrombectomy device, and wherein the proximal endof the working length is distal to and spaced apart from the proximalend of the thrombectomy device.
 34. The medical device of claim 33,wherein the projection is within 5 millimeters of the proximal end ofthe working length.
 35. The medical device of claim 27, wherein thethrombectomy device is configured to self-expand.